Compression therapy (CT), is the selective external compression of a portion of the body using wraps, stockings, inflatable cuffs and bandages. CT can be either passive compression using elastic or inelastic bandages or multiple layers of bandages (no external energy applied) or active, where an external energy source augments a compressive force applied to body part(s), as shown in FIGS. 1A-E. CT is used to treat many conditions including: vascular insufficiency (both arterial and venous) as shown in FIG. 2, lymphedema, post thrombotic syndrome, DVT prophylaxis, post op pain/swelling, leg swelling, varicose veins, enhance blood circulation, intermittent claudication, inoperative peripheral arterial disease, post-operative swelling, congestive heart failure, sport/exercise recovery, and massage.
Examples of the some of the commercially available compression bandages currently available include those made by 3M, BSN Medical, Convatec, Derma Sciences, Hartman group, Kendall/Covidien, Lohmann and Rauscher, Medline Industries, and Smith and Nephew. The compressive force of compression bandages is achieved in the application or wrapping of the bandage by a caregiver. The consistency of the compression is dependent on the skill of the caregiver applying the bandage. There is no feedback on the amount of compressive force applied with bandages. The patient is wears the bandage until the stocking loses its compliance or become soiled. Bandages are typically applied to the arms or legs.
Compression stockings (CS) are elastic stockings that are typically placed over the lower leg like long length sock or leg hosiery. The stockings are marketed to provide a specific level of compression, often greater compression at the ankle with reducing levels of compression toward the knee to compensate for the higher hydrostatic pressure toward the ankle when standing.
CS can be designed to provide a range of pressures to the lower leg. For example, a CS that delivers light compression can provide less than 20 mmHg of pressure; moderate compression is between 20 to 40 mmHg, strong compression between 40 and 60 mmHg and very strong compression can be over 60 mmHg.
Manfacturers offer a variety of compression levels up to 60 mmHg. Some manufacturers of CS include Bauerfeind, BSN, Kendell/Covidien, and Sigvaris.
Active compression (AC), often referred to as pneumatic compression devices use air chamber containing sleeves that enclose the patient's leg or foot. The three main categories of AC are foot pumps, that compress the venous sinus of the foot, intermittent pneumatic compression (IPC) that inflate and deflate the entire sleeve at the same time and sequential compression pumps (SC) that sequentially inflate chambers in the sleeve to move the blood (or milk) the blood toward the foot to enhance arterial flow, or toward the waist to improve venous, lymphatic fluid or enhance removal of lactic acid post-exercise.
AC devices are made in both plug-in and battery-powered mobile units as shown in FIG. 2. With the exception of the Venowave, which uses a roller to roll the calf, the pneumatic compression devices typically operate in the same manor. A pneumatic pump fills a bladder or series of airtight bladders that is controlled via a console.
There is strong evidence that all these forms of compression therapy are helpful in treating or preventing the conditions for which they are used. The significant deficiencies that all of these technologies suffer from is unknown/inconsistent pressure application, poor comfort due to bulky, non-breathable cuffs and difficulty in donning/doffing the stockings or wraps. These design deficiencies result in non-compliance with the technologies, estimated to be as high as 70%. The root cause for poor compliance with compression therapy is multi-factorial. Standard tight fit stockings are hard to don/doff for someone who already has limited mobility due to their disease. Some clinicians resort to recommending that patients apply KY jelly over the leg to help don/doff the stocking, as well as using an external donning/doffing aid, such as a Jobst Stocking Donner (Model number 110913). In addition, although these stocking can be provided in multiple sizes, to the stockings often have problems with poor fit, including areas that are too tight causing pain or too loose causing the stocking to droop. Inelastic compression wraps (e.g. Unna boot) where the lower leg is wrapped in a series of layers of cotton wraps with zinc oxide and other compounds, are not well tolerated by patients either as they are rigid, uncomfortable, can develop a foul smell due to accumulation of exudates from the ulcer and must be changed weekly. Inelastic compression wraps have an additional burden as compression wraps must be changed often, which typically requires the patient to travel to a venous clinic and utilizes expensive nursing resources.
With millions of affected patients affected in the US and billions of dollars spent attempting to treat patients with poorly understood treatment regimens with devices that patients are reticent to use due to discomfort, there is clearly a need for a better technology. Therefore, there is a need for an innovative, multi-mode compression therapy system that addresses these problems.